Drug abusing patients who have been exposed to tuberculosis (TB) are at high risk for developing active TB disease, therefore constituting a high priority group for preventive treatment. Poor compliance with prophylactic treatment leads to poor health, engaging in high risk behavior, and increased risk for hepatotoxicity, sexually transmitted diseases and HIV. The goal of these studies is to determine whether contingency management interventions on drug use, as adjuncts to standard (but enhanced treatment), will decrease drug use and increase compliance with the prophylactic TB treatment in two groups of cocaine-dependent TB positive patients. The primary specific aims of these studies are to examine the relative efficacy of contingency management interventions on cocaine use, as adjuncts to standard (but enhanced treatment) in: (1) decreasing cocaine use, (2) enhancing retention in treatment and (3) enhancing compliance with a prophylactic TB treatment regimen in two TB-positive cocaine- dependent populations. There are two parallel studies. Study 1: will compare the effectiveness of 2 contingency management interventions on drug use, as an adjunct to standard (but enhanced treatment), to each other and to a control condition consisting of standard (but enhanced) treatment alone, on decreasing drug use, enhancing retention in treatment and increasing compliance with prophylactic treatment. Patients will be randomly assigned (after stratification on drug status at intake (a measure of severity of drug use]) to one of 3 treatment groups with 14 patients per group. Patients in Group 1 will be reinforced monetarily with a constant magnitude reinforcer for cocaine- free urine samples, with an additional weekly reinforcer for consecutive cocaine-free samples. Patients in Group 2 will be reinforced with an innovative shaping procedure, where successive decreases in cocaine metabolite (benzoylecgonine) levels and cocaine-free urine samples are reinforced. There is an additional weekly reinforcer for continuous decreases in cocaine-metabolite or cocaine-free samples. There will be no contingencies on cocaine use for patients in Group 3. This study will be conducted in TB positive patients with a primary diagnosis of cocaine dependence. Study 2: parallels Study 1 and will be conducted in TB positive patients with a primary diagnosis of opiate dependence and secondary cocaine dependence. Methadone (individualized doses) will be the treatment of opiate use. As in Study 1,there will be 3 treatment groups, with 31 patients per group. All patients: will receive a baseline standard drug treatment consisting of weekly counseling sessions, and prophylactic TB treatment, consisting of isoniazid (INH) which will be dispensed at the drug treatment clinic, under directly observed therapy. Patients will participate in the studies for 6 months, standard duration of INH treatment. Comparisons will be made across groups on drug use, retention in treatment and compliance with preventive TB treatment. These studies will identify effective treatments to reduce drug abuse and increase compliance with prophylactic TB treatment, thereby minimizing risk of harm. Interventions that are found to be effective will have major health care implications.